docs: update

README.md

@@ -1072,8 +1072,11 @@ dirname() {
     # Usage: dirname "path"
     dir=${1:-.}
     dir=${dir%%${dir##*[!/]}}
+
     [[ "${dir##*/*}" ]] && dir=.
+
     dir=${dir%/*}
+    dir=${dir%%${dir##*[!/]}}
 
     printf '%s\n' "${dir:-/}"
 }

manuscript/chapter5.txt

@@ -11,8 +11,11 @@ dirname() {
     # Usage: dirname "path"
     dir=${1:-.}
     dir=${dir%%${dir##*[!/]}}
+
     [[ "${dir##*/*}" ]] && dir=.
+
     dir=${dir%/*}
+    dir=${dir%%${dir##*[!/]}}
 
     printf '%s\n' "${dir:-/}"
 }

test.sh

@@ -144,6 +144,12 @@ test_dirname() {
 
     result="$(dirname "something/////////////////////")"
     assert_equals "$result" "."
+
+    result="$(dirname "something/////////////////////a")"
+    assert_equals "$result" "something"
+
+    result="$(dirname "something//////////.///////////")"
+    assert_equals "$result" "something"
 }
 
 test_basename() {